The present invention relates to a drive assembly for the wing of a swing-out type sliding door. More particularly, it relates to such a drive assembly especially intended for a swing-out type outer sliding door for vehicles.
In conventional swing-out type sliding doors, a roller carriage is mounted in an articulated manner approximately in the center of the vertical edge of the wing of the door. The roller carriage runs on a guiding rail mounted on the outer side of the body of the vehicle during opening and closing of the door. In addition, in most cases, the wing of the door has additional top or bottom guiding means permitting the wing to be safely guided into the doorway. Such swing-out type sliding doors are driven with the help of a piston-and-cylinder type or an electrical drive, which, in turn cooperate with a rack-and-pinion drive. However, with drives of this type, the problem exists that in the final phase of the sliding motion, resistances have to be overcome in the closing direction, the resistances being caused by the sealing of the door. This means that the wing of the door may have to be pushed into the doorway with a certain minimum speed, so that due to its force from inertia, it is capable of overcoming the resistance offered by the sealing of the door. Otherwise, special door closing aids which pull the wing of the door into the doorway have to be provided. In any case, special measures are required in order to permit the door to be properly closed.
This problem cannot be eliminated by boosting the piston-and-cylinder drive or rack-and-pinion drive because the force of the drive is substantially acting parallel to the plane of the door, whereas in the final phase of the door-closing operation, the wing of the door is substantially moving perpendicular to the plane of the door. This means that in the final phase of the closing action, the component of the driving force perpendicular to the plane of the door is close to zero.
Accordingly, it is an object of the invention to provide a drive assembly for the wing of a swing-out type sliding door, wherein the closing action can be properly executed without any special aids.